In various kinds of exercising and fitness training, it has become common to measure the heartbeat with various handheld measuring devices based on wired or telemetric wireless transmission between a separate transmitter attached to the body and a receiver worn on the wrist. Such a device is described in U.S. Pat. No. 4,625,733, for example.
On the other hand, it is known to combine the use of programmable exercise devices, such as cycle ergometers, with the use of pulse measuring devices, such as in U.S. Pat. No. 5,067,710.
One very significant index of an individual's level of fitness is her or his mean pulse value calculated on pulse values measured during a whole exercise performance. This kind of index is, however, not useful if the performance varies from one time to another, which it invariably does in sports, due to outer circumstances, such as weather, disturbance from other people, mistakes by the performer himself etc. Looking into this problem the other way, there has so far not been a reliably and easily calculated index for indicating a constant level of heart performance at each fitness test occasion; which means that a certain heart performance index is the target and the exercise is continued and/or varied in order to achieve this target index.